Study On The Detection Method Of EMC For Centralized Meter Reading Terminal

Setting up an efficient, stable and secure power system is power grid corporations’ objective. In recent years, with the rapid development of electronic technology, the harm caused by electromagnetic interference problems are increasingly exposing. How to achieve the electromagnetic compatibility between electrical equipment is a main part of interdisciplinary research. As an important component of the smart grid, centralized meter reading terminal’s electromagnetic performance is a great significance for the optimization of power quality. Meanwhile detected the electromagnetic compatibility of the centralized meter reading terminal is an important part of EMC research on such equipment.However, the centralized meter reading terminal is a product developed for the needing of the Chinese smart gird. There are no similar foreign products. Domestic and international existing electromagnetic compatibility testing methods can not be directly applied to such equipment. Thus, it is necessary to design and develop an efficient, scientific testing method for the concentrated reading terminal equipment by integrating the existing electromagnetic compatibility testing technology, to fill the gap in this field.In this paper, the basic concept and the rules and regulations of electromagnetic compatibility are reviewed. The restrictions relating to electromagnetic compatibility are defined. The questions of electromagnetic compatibility have been summed up, including sensitive equipment, anti-jamming performance, characteristics of disturbance source, electromagnetic compatibility measurements, the propagation characteristics of electromagnetic disturbance, electromagnetic compatibility within a system or between several systems.Meanwhile, the concept of the centralized meter reading terminal is interpreted. It has explained the working principle and hardware design of the centralized meter reading terminal, and analysed the terminal type of interference analysis around the presence of concentrated reading. This paper also has pointed out that the electromagnetic interference of the centralized meter reading terminal including interference with radio-frequency radiation, conduction disturbance interference, lightning surge, electrostatic discharge immunity and electrical fast transient interference. Conductive coupling and radiation coupling, the two main transmission ways of the electromagnetic interference have been instructed.Aiming at the five interferences existing around the centralized meter reading terminal, combined with the corresponding standard, we have designed five electromagnetic compatibility testing programs for the centralized meter reading terminal, and made practical application for verifying. The experimental results show that the testing programs can satisfy the demand of the electromagnetic compatibility’s technical specifications, and ensure the reliability of the equipment.To deal with the difficulty of the detection of the presence of interfering signals, we have proposed the application of wavelet analysis for electromagnetic compatibility testing and diagnosis. Wavelet decomposition is used to simulate the electrostatic discharge interference EMI. Experimental results show that wavelet analysis in electromagnetic compatibility testing is effective.